1. Field of the Invention
This invention relates to interfacing hardware and software components in a text information system and more particularly to interfacing a keyboard with software components.
2. Description of Prior Art
An electro-mechanical keyboard is a common means for operator interfacing with other components in an information system, such as a computer or text processing machine for inputting information and directing operation of the system. In some cases, the keystroke generation rate in the keyboard and the keystroke processing rate in the remainder of the system is asynchronous. If the keystroke generation rate is greater than the keystroke processing rate, keystroke information may be lost. This problem may be greatly alleviated or solved by providing a keystroke queue for storing generated keystroke information until processed.
However, many keys on a modern keyboard include a typamatic function. When the typamatic function is actuated, the keyboard hardware generates an initial nontypamatic keystroke and, after a short delay, repeated keystroke information as long as the key is held down by the operator. In a text processing machine, for example, vertical and horizontal cursor function keys are provided with a typamatic function to permit location of a cursor on a display of textual material. In a machine having a keystroke queue, the actuation of the typamatic function of a cursor key permits the entry of a number of cursor keystrokes into the keystroke queue in addition to the processed cursor keystrokes as represented by movement of the cursor on the display. This leads to an overshoot of the desired cursor position as the keystrokes processed and perceived by the operator on the display do not match the keystrokes generated.